Supplement Savvy: Part 1 When To Supplement

No producer likes to spend money on supplemental feed for cows. But, as forage becomes dry, dormant or scarce, it may be necessary. To help you design a budget-conscious protein supplement program for cows on grass, two cattle nutritionists share, "What works best?"

When To Supplement "Normally, feeding supplemental protein is necessary and justifiable when the available diet does not meet an animal's nutritional requirements," says Ed Huston, an emeritus beef cattle nutrition professor from Texas A&M University.

That typically occurs when grass pastures become dry and dormant, and protein content in the plants drops off, says Jan Bowman, a beef cattle nutritionist at Montana State University.

"If there's a lack of forage due to drought, or when forage gets dry in late summer, feeding cattle supplemental protein can give a boost to forage intake and digestion. It's meant to complement the forage," she says.

Protein supplements also can be important with winter grazing. "Dormant winter range forage is usually very low in protein, making a protein supplement beneficial," Bowman says.

The periods of calving through breeding are also critical nutritional periods for cows, "but if you are feeding a good-quality hay during that time, the protein content may be enough that another supplement isn’t needed," she adds.

Both Huston and Bowman say a common mistake producers make is providing supplement when cows don't need it.

"Often, personal preference leads producers to feed more supplement than is necessary for economic return," Huston says. "Much of it hinges on how a producer reacts to seeing a fat cow vs. a thin cow."

To know when protein supplements are necessary, Huston says, takes a critical eye. In a cow-calf operation, watch the cow's condition. A body-condition score (BCS) of 4 to 6.5 is a good target. If her BCS gets above or below that, something needs to be done. In a stocker situation, rate of weight gain is typically a good indicator of whether supplemental feed is necessary.

Bowman adds, "Evaluate the protein content of the available forage and estimate how much animals are consuming to determine how much protein they are getting." As a rule, high-producing cows need up to 3 lbs. of crude protein/day during lactation, she says.

How Often To Supplement "Most nutritionists agree that it's best for animals to have all the nutrients they need every day. However, infrequent supplemental feeding of cattle on pasture — three times a week or weekly — produces satisfactory performance and actually has some benefits," says Huston.

He reports that performance of cows fed a weekly protein supplement is comparable to that of cows supplemented daily or three times a week. "We haven’t found any ill effects of feeding a week's worth of protein supplement at one time," Huston explains. For instance, rather than putting out 2 lbs./head/day, you're providing 14-15 lbs./head at that one weekly feeding. "We’ve traced blood/urea levels, which are a good indicator of protein status of the animal, and found that after consuming the weekly feeding, the animal’s blood urea level goes up and stays high for five to six days."

"So, we know offering a weekly protein supplement gets them well-dosed with protein, like stockpiling, and by the time the animal's blood/urea level goes back down it is within a day or two of being supplemented again," he says.

Huston says the advantages of weekly feeding over daily feeding are decreased time and labor expense. Another benefit appears to be an alteration in the animal's behavior pattern.

"When animals are fed daily, you often find them waiting at the gate or running across the pasture to meet the feed truck, which reduces grazing time," Huston explains.

"We also seem to get a better distribution of feed among animals that are fed infrequently, due to a reduced bullying effect," he says. He explains that the perceived unlimited amount of feed — compared to putting out a limited amount — likely causes animals not to fight and instead eat in peace. The bottom line, Huston says, is that infrequent feeding works well with protein supplements.

"Feeding three times a week is the optimal, but weekly feeding is less expensive than daily feeding and offers satisfactory performance," he says. The only caution is to be certain none of the ingredients in the product are dose related for health. If an ingredient needs to be fed in low doses on a frequent basis, a once per week feeding would be lethal, Huston explains.

Also, energy supplements shouldn't be offered in large, weekly amounts to prevent the animal from overeating starch and getting sick.

How About Self-Fed Supplements? The convenience of self-fed or self-limiting supplements has helped bolster their popularity, but individual intake can vary widely with such systems. Some cows may not consume any supplement, while others may consume large amounts, cautions Montana State’s Bowman.

When feeding a form of supplement that targets individual consumption, if animals don’t eat it, they may not get the nutrients they need. Or, some animals may be eating too much and costing the producer money, she says.

Bowman says most commercial products have an intake limiter in them, which helps minimize over-consumption. She adds that making sure there are enough tanks or blocks for the number of cows will reduce variation in intake, and adds, "In several studies that we've conducted with self-fed supplements, we’ve seen very uniform intakes."

However, those animals that don't consume the supplement — and need it — can be a concern.

To address that dilemma, she suggests introducing animals to the supplement in a drylot setting before being put out on range; placing the supplements in areas animals will frequent — near water or preferred grazing areas; and sorting older boss cows into separate groups from younger animals that may require more supplement.

When considering self-fed supplements, Bowman also offers these tips:

1) Match the product's target intake and protein content with the amount of supplemental protein needed.

2) Price supplements per pound of protein, as you would do with other feeds.

3) Some self-fed products will put a trace mineral package in the product which increases costs. That package may not be necessary if you already have a mineral program in place, she points out.

4) Feeding supplements infrequently, like Huston suggests, may be another alternative. The ability to feed weekly or three times per week can reduce labor costs associated with hand-fed supplements, Bowman says.